LIC1A-Conclusion

=Long Island Creek Site 1A - Conclusion=

The interesting part about Site 1A is that it appears to be a simple ditch situated at an elevation of 1037 ft within an average residential neighborhood when, in fact, it actually is the headwater of the Long Island Creek watershed. More interesting is that this neighborhood ditch also is a headwater of the Chattahoochee watershed. The health of the innocuous ditch plays a significant part in the health of Sandy Springs' rivers, streams, and ecosystems. This investigation provides evidence that the erosion control procedures utilized clearly work. Although the wooden retaining wall works, it is in need of repair. Yet, the large rocks and English ivy restoration have been proven to resist erosion and maintain stability over time without the necessity of repair. The adjacent watershed in this site area is predominantly lawns and gardens, which allow rain water to be absorbed into the environment. However, the larger perspective of the site shows paved driveways and roads as well as nearby commercial developments in the watershed that makeup a large percentage of impervious surfaces feeding rain water into Long Island Creek. The impervious surfaces expel rain water rapidly and carry heat and pollution into the stream.

The chemical and physical results for Site 1A reflect the heat and pollution problems and were limited by the ephemeral nature of this stream. The following days brought extremely hot, dry weather, which further impacted data and the ability to collect data. Considering these facts, the pH balance for the two days of collection were 6 and 6.5, indicating a small tendency toward higher acidity levels. The water temperatures were relatively high, at 21 degrees Celsius, due to low water amounts, runoff from paved surfaces, and heating from sunlight and the ambient outside temperature. The Dissolved Oxygen levels measured 3.75 and 4.2 parts per million (ppm) on the first visit and 2 and 2.25 ppm on the second visit. The first Dissolved Oxygen reading results, which were taken just after a rain event, reflect levels that fall at the edge of the normal range. However, the second visit reading results fall below healthy oxygen levels and indicate hypoxic tendencies. Conductivity measures the ability for the water to pass electric current and is defined in microsiemens per centimeters. Healthy levels are between 150 and 500 μS/cm. The readings from Site 1A are 90 and 90 μS/cm at the first site visit and 70 and 80 μS/cm at the second site visit. These readings indicate poor stream water conductivity.

The bacterial results show Coliform counts of 1433.3 on the first site visit and 1166.7 on the second site visit. The first site visit took place after a series of storms passed through the area, which likely accounts for the higher coliform levels for these test results. Although the stream water had evaporated, the coliform levels were actually reduced, indicating that residential pet waste washed into the streams during the rain, elevating the coliform levels. As the water pooled, the debris settled out.

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